Comparability of some serum protein determinations by radial immunodiffusion, laser nephelometric and turbidimetric assays employing Q-antisera SEVAC.

Quantitation of IgG, IgA and IgM immunoglobulins and C3, C4 components in human serum samples by the radial immunodiffusion technique and by the nephelometric and turbidimetric assays was compared using the linear regression analysis method. Comparisons of the two methods run in polyethylene glycol showed close agreement between methods and a relatively high degree of correlation between the parameters studied. Compared to the radial immunodiffusion technique, nephelometry and turbidimetry gave good correlation between parameters, but the agreement between tests was worse, especially in the case of C3 component determinations in fresh samples of patients' sera. All tests were carried out using the Q-antisera and Control human serum preparations SEVAC.